HC-SCR is a technology designed to reduce primarily Nitrogen Oxides (NOx) emissions from internal combustion engines
(specially diesel engines). Unlike urea-water solution injection in a conventional SCR system, hydrocarbons is
injected in the exhaust stream as a reducing agent in the HC-SCR system. HC-SCR is becoming increasingly interesting
in the context of meeting stringent environmental standards, such as Euro 7, BS7, etc.
How HC-SCR Works
HC-SCR systems primarily focus on reducing unburned hydrocarbons in the engine's exhaust. The process occurs over a
specially designed catalyst, typically containing precious metals like platinum or palladium. The catalyst
facilitates a chemical reaction between the hydrocarbons and NOx emissions breaking down NOx into nitrogen and water
vapor. Partial oxidation of the hydrocarbons improves the reaction efficiency.
Advantages of HC-SCR
- Compatibility with Diesel and Gasoline Engines:Although HC-SCR was initially more commonly used in
diesel engine applications, advancements in catalyst technology have made it applicable to gasoline engines as well.
- Cost-Effectiveness:Compared to other emission reduction technologies, HC-SCR systems are generally
cost-effective to implement and maintain, especially when considering the long-term environmental benefits.
Applications of HC-SCR
- Automotive Industry: The primary application of HC-SCR is in passenger vehicles, trucks, and buses,
where it is used to meet stringent emission regulations. In commercial trucks and industrial applications, HC-SCR is
a key technology to meet environmental regulations that mandate reduced NOx and HC emissions.
- Off-Road Vehicles: HC-SCR is also increasingly used in off-road and construction vehicles, which are subject to similar environmental regulations.
Future of HC-SCR
- As emission standards become more stringent, HC-SCR systems are likely to evolve further. New developments in
catalyst materials, reductant technology, and system integration could enhance the efficiency, cost-effectiveness,
and ease of use of HC-SCR systems, enabling automotive industry to meet even more demanding environmental targets.
- HC-SCR offers a sustainable pathway for reducing NOx emissions, especially in applications where traditional Urea
base SCR systems may not be feasible
- Additionally, HC-SCR may also find applications in hybrid vehicles where a combination of internal combustion and
electric propulsion requires advanced emissions treatment.